This invention relates to a method of treating the African trypanosomiasis disease usually referred to as sleeping sickness when it occurs in man. Specifically, this invention relates to the discovery that certain phosphonium salts possess anti-trypanosomal activity.
African sleeping sickness is an endemic and occasionally epidemic infectious disease which is progressive and usually fatal if untreated. The disease is caused by either of two protozoan species, Trypanosoma gambiense or T. rhodesiense, and transmitted by the bite of the tsetse fly. The disease is confined to the African Continent and a few adjacent islands, and even then is restricted to the tropics. It has had continuing effect on the history of tropical Africa. For example, it is estimated that in an area of over 2,000,000 square miles, draft animals are virtually absent. Furthermore, the protein malnutrition of tropical Africa has been traced in part to the partial vegetarianism enforced on a society in which it is impossible to rear the common comestible animals owing to diverse trypanosome infections of man's animals.
Although partially effective drugs are available for therapy and prophylaxis, all presently employed drugs have very serious, toxic side effects. Less toxic, more effective chemical agents are needed urgently.